Gear grinding machine



Dec. 9, 1952 J. RILEY 2,620,599

GEAR GRINDING MACHINE:

Filed March 29, 1950 5 Sheets-Sheet 1 Dec. 9, 1952 J. RILEY 2,620,599

GEAR GRINDING MACHINE Filed March 29, 1950 5 Sheets-Sheet 5 Patented Dec. 9, 1952 OFFICE GEAR .GRINDING MACHINE Joseph Riley, Staines, England, assignor to W. E. Sykes Limited, Staines, England Application March 29, 1950, Serial No.152i580. In Great Britain Api-i177, 1949 'Cla-ims. 1,

Thislnvention' relates to machines'i'origrinding spur or helical'gear tooth proles by a generating method', ofthe kind in.r which theV workand a grinding wheel.y of' disc, orA similar formarereL ciprocated'relatively in the general directionl of the plane of the wheel to grind a tooth iiank or'ilanks; the workibeing moved with a.rolling motion' by indexing' or dividing means transversely tol tlie' direction ,of'the aforesaid vrelative rciprocation; andthegrinding wheelhaving a profile'v correspondingtok that of the basic rack tooth ofthe tooth profile being ground. For grindingspur teeth, the direction of relative re;- ciprocation isparallel to the raxis of the work, and'for helical teeth the direction of relative reciprocation is` inclined to. said axis. The profile ofthe grinding wheel may be such that it can grindone tooth flank only, or it can be formed to. grndthe anksiof two adjacent teeth simultaneously.

The object ofthe invention is to providevan improved` machine of the above kind'which is capable ,ofg-rinding gearsor gear shaper cutters which-.are of conicalior non-cylindrical or tapered form. Another object is to provide a machine capable of grinding gears of conical form andparticularly gear Shaper cutters in a simple and economical manner.

VThe invention consists in providing means for effecting` the required relative reciprocation between the work andthe grinding wheel in a, direction which is inclined to the axis of the work suchthat a conical or similar gear or gear Shaper cutter is produced.

The invention also consists in providing means for reciprocating the grinding wheel relative to thework in a direction which isl inclined to the work axis such that agear or gear shaper cutter of non-cylindrical and conical form is prodced..

According to a further feature of the invention, means isy provided. for adjustably varying the inclination ofthe relative motion between the work 'and'grinding wheel in orabout the plane of the grinding wheel 4so that gears orv cutters of different' conical or like form can be produced. This may be effected for example, by mounting thegrinding wheelon a reciprocating slide the inclination of'which. relative' to the work axis can beadjusted in the plane of the wheel or a plane approximatingtliereto.

According to a further feature. of' the invention, nreansisprovidedfort adjustably varying the inclination ofi' tlieA relative motion between the workand grinding wheel in or aboutV the plane of the 1 grinding wlieel` axis so i that helical fteeth can be produced. This may beeifected'for example by mounting -the grinding wheel cna-reciprocating slide whichis itself carried by v a circular slide which can be angularly adjusted aboutan axis` which isV transverse to thev plane of the grinding wheel axis;

Any convenient or known means forindexing or dividing the work-and forv controllingitsy rolling motion may be employed, but preferably the controllingmeans comprise-a steel tape orrtapes co-operating with al drum on the work spindle; the work being carried in ahead which 'is displaced transversely with respect to the work axis so that the requiredrolling motion is obtained.

Inl one convenient arrangement according to the invention, the workcarrying spindle is supported horizontally in a head which is displaceable upon av slide in a'direction transverse to the work axis, the rotation'of the'work spindle'being controlled by a steel'tape andA drum arrangement of known kind to obtain'the-rolling motion required; The grinding wheel is carried upon a sliding head, the slideway of which is inclined with respectto the horizontal so that'the teeth cut and the roots thereof will be of conicalform.

It is also preferred'to include means for adjusting the distance of the grinding wheel slide from Atloe-vvork axisfforvarying the depth of cut and also for periofgiically-movingk the grinding .wheel'jslide-away from thework axis to separate the wheel and work during the indexing or dividing displacement ofthe work gear.

In the accompanying drawings,

Figures l; 2"and`3 are diagrammatic end* elevationsy of three involute-gearsy having the same tooth characteristics but of differentoutside di` ameters;

Figure 4 is a side view, more or less diagrammatic, ofalaminated gear of conical form;

Figure-5is an end view of-such a gear;

Figure 6 is a side View of a laminated gear simi-- lar'to vthat of Figure 4,' in which the laminations are relatively displaced angularly to form a helical gear;

EigureH-'isa sectionalside elevation of a-mafchine lconstructed inaccordance with the invention for grinding spur or helical geartooth proiiles;Y

Figure 8 is a` sectional endelevation ofthe inachine-takenon the line-8r8 ofliigure-T.

It isfknownthat'involute gears `havingthesanrie number of "teeth, the samebase circle diameter, andihaving' a gear tooth formwhich can-beenfclosedin the same rack toothY form; can be gen- 3 erated to have different outside diameters. Examples of three such gears are shown in Figures 1, 2 and 3. The involute form of each gear is based on the same base circle Do and in each case the gear ltooth is based on the same rack tooth form A. The outside diameter D1 of the gear shown in Figure l is greater than the outside diameter Dz of the gear shown in Figure 2, and the outside diameter D3 of the gear shown in Figure 3 is less than Dz. If a number of gears are produced as thin laminae having their outside diameters varying progressively from D1 to Da and these are assembled in their progression of diameters with the axes of symmetry of the gear teeth in line, a gear will be produced as shown diagrammatically in Figures 4 and 5 having an outside diameter of conical form, a constant cylindrical base circle diameter, and the same rack form equivalent at any diameter of the conical form. Also, if the axes of symmetry of the gear teeth of successive laminae are given an angular displacement, a helical gear of conical outside form will be produced as shown in Figure 6. Gears of this form have numerous uses, particularly for use as gear Shaper cutters, and this invention is concerned with means for forming such gears or `cutters by the generating principle.

The invention will be described as applied by way of example to a gear grinding machine of generally known kind and is illustrated in Figures 7 and 8. Such machines comprise a frame I upon which is mounted a head 2 formed with or carried by a cross slide 3 which can be reciprocated in a guide or slideway 4 in the top 5 of the frame I. Any convenient means may be provided for reciprocating the slide 3 and in the present example these'comprise a connecting rod B between a pin 1 on the slide and a pin 8 on a crank disc V3 secured to a vertical shaft Ill. A worm wheel Il is secured to a shaft I2 coupled at I3 to the shaft I and is driven by a worm la from an electric'motor I5. The shaft is supported in a bracket I 0a. Change speed gearing may be incorporated in the motor drive if desired, or the motor may be of the variable speedtype. The work gear l5 to be formed is mounted on a spindle I1 .iournalled in a sleeve I8 which is itself journalled in the head 2. The spindle I1 has a collar I5 to which is secured a dividing or indexing plate by means of a pin ZI. The plate 25 is formed with peripheral notch-es 22 which canbe engaged by a latch 23 pivoted at 24 on a disc 25 which is keyed to the sleeve I3. A drum 26 is keyed to the sleeve I8 and secured to the drum surface'are flexible steel bands 21, the ends of which are anchored to'brackets 23 secured to the frame top 5. The means for anchoring the bands comprise bolts and lock nuts 29 secured in vertical slots 3B formed in the brackets 28. It willbe understood that as the slide 3 isreolprocated, the drum 26 will be constrained to roll on the bands 21, thereby giving to the work gear I5 a rolling motion as if the gear were rolling over a stationary rack. To advance the work for the generation of successive tooth spaces, the latch 23 is lifted and the plate 20 is revolved to engage the latch in the next notch, the number of notches in the plate being equal to the number of teeth to be formed in the Work gear. It is to be understood that any convenient or known means may be provided for operating the dividing or indexing mechanism and such may be controlled by a counter if desired. Also other indexing arrangements may be employed.

According to the invention the grinding wheel 3 l, which in the present example is of trapezoidal section as indicated in Figure 8, is rotatably mounted in brackets 32 on a slide 33 and is driven from an electric motor 34, also mounted on the slide, by a belt 35. The slide 33 is slidable longitudinally, i. e. the general direction of the plane of the grinding wheel 3|, in a slideway or guides 35 in a pivotally mounted slide support 31 which is arranged so that the engaging slide surfaces yare inclined with respect to the axis of the work carrying spindle l1. The slide support has depending bearings 35 at one end seated upon a pin 39 which is supported in brackets 45 secured at one end of a table 4I. The other end of the slide support has a depending arm or arms 42 formed with an arcuate slot 43 in which is engaged a bolt 44 whereby the arm or arms can be secured to the table 4I with the slide at any desired inclination. For reciprocating the slide 33, a motor 45 is mounted on an extension bracket l5 of the slide support 31 and drives a worm wheel 41 on the shaft 48 to which is secured a crank disc 49. A pin on the slide 33 is connected to a pin 5I on the crank disc 49 by a connecting rod 52.

The table which carries the grinding wheel assembly previously described is mounted to permit of angular adjustment about a vertical axis. For this purpose the table is formed with a bottom plate 53 having a central aperture and constituting a circular slide which is guided by a spigot 54 about which the slide is adjustably displaceable. The spigot 54 forms part of a table support 55 on which the circular slide 4| rests. This table support is vertically movable and is guided by slides 56 and 51 in xed vertical guides 58 and 59 which are secured to the base structure 60, the latter being integral with the main frame l. The table support 55 is maintained in position by a thrust shaft 6I having collars 62 which engage the table support, and the lower end of the shaft having a screw thread 53 which is engaged with the internal thread of a vertically movable nut member 54 having a key 55 slidable in a vertical keyway 56 in a housing 61, whereby rotation of the nut member 64 is prevented.

The thrust shaft 5I has secured to it a Worm wheel 23 with which is meshed a worin 69 on a transverse spindle 1E carried in bearings in the table support 55 and having a squared projecting end 1l which can be rotated by means of a suitable key. By this means the thrust shaft can be rotated in the nut member de to move the table support 55 vertically and thereby the depth of cut of the grinding. wheel 3i .can be varied or adjusted as desired.

The vertically slidable nut member @A rests upon and is supported by a cam 12 secured to a shaft 13 carried in bearings 'lil forming part of the housing t1. The other end of shaft 13 is supported in a bearing 15 and has secured to it a bevel gear V meshing with a bevel gear 1l on a shaft 15 which also carries a bevel gear i5 meshing with a second bevel gear 55d on a vertical shaft 8l connected by a coupling S2 to the shaft VI 2 previously described. The arrangement is such that towards the end of the reciprocating motion of the slide 3 which carries the head 2 and work spindle il', the rotation of the cam 12 causes the table support 55 and its slides 55 and 51 to be lowered, thereby lowering the grinding wheel 3! so that the latter is withdrawn a substantial distance from the work during the dividing or indexinggoperation which is effected by raising of d theT latch: member'. 23.: asI previously; described'. Wfhen: theg motion of.;'the. slide; 3; is.I reversed, the car-nV 72( again raises; the` grinding wheel. to its formerV position ready; for: anotherv generating operation assthe-head f2f. perf orms.r afurther.- stroke inrthe opposite direction.'--

Thezoperation ofy the :machine .willbe clearrirom the.;` foregoing:` description of the various. parts thereof; If? theglineoi reciprocation foigzthegrind'- ing-wheel werefto begin' thefhorizontalplane (the horizontal. plane being that. which. contains 1 the matingsuriacespil the circular table iff` and the support iythezworkjaxis beingfinaplane ,parie allel to; saidi` horizontal plane,V them cylindrical gears either of: straight.: on helical form couldrbe produced.. dependent; on the setting cfg-circular tablef, 53.". their supncrti. ltiwillibeyseemthat with thefarrangementshowrrgin. ther-drawings, .as thefrotatingA grindingwheel isrec'iprocazedzoniits slide33, itsxasiis` at ,g any,A part` of. the stroke rwillbe at. rafgreater: or; lessY dista-nceifrom vtliesafxisoi; the work gear.1 l 6,- aooordingg to thean-gle at iwhichsthe slideway 3S, ish secured. by- Y adjusti'nentty of' the; slot 43.byfmeansof:the=bolt 34.. Gonical orA tapered gears or gearshaper .cutters vwill .thus be produced either of straight-.or helicallform'dependent" on the. setting; of the-circular, table `53-on .its support 551;. The." operationiof the indexing or'dividing meanssand'thefmeans ffor. adjusting-'therdepth of cut andior.y withdrawing. thesgrinding-.zwheel =dur ingAv the indexing displacements 1 aref well; known and it is not thought: to bef necessary to :describe these in detail.y

It willbeY understood ithat the required relative motions for producing conical or likegears'may beobtainedin other-ways.l T-hus, for-example, the grinding wheel slide-may be' arranged Sorthat the direction of its-reciprocation is horizontal, as in thegenerally known-machines, and the slideway, of the-cross slide oarryingthe` work head may be formed as: a pivotallyi mounted4 structure, the pivotal axis beingV4 horizontal'v and transverse to the work-axis, the: arrangementlbeing such that the. inclination of the 'workY axis: to -the direction of reciprocation of thegrinding` wheel canbe'adjustedlasdesired to produce .gears Aori gearvv Shaper cutters of non-cylindrical and-conical form.t The pivotally mounted structure aforesaid. also carries the frame lto .which the steel 1tapes 'fori controlling the generating: motion .l of thef work lare anchored:`

Bythis: invention, involute' gears: of conical, tapered and like-forms can be ground inaisimple and .economical manner; and :the invention'is ap-v plicablexwithparticularJadvantage to the. production -oi gear- Shaper.cutters.` The invention 'isf not restricted. however,V tov thefy example described,

since-fl the recpiired.v relative i motions: of the' workandigrinding-,zwheel can 'be'zeiected Lin' .many ways.- Thus for-1 example-thefwork can be reciprocated with respect to the, grinding wheel,- and the reciprocationsr^can;beeifected by other than mechanical means, for example by hydraulic mechanism. Also whilst theinvention has4 been described as applied toa machine having-@grinding `wheeler trapezoidal form which grinds'. opposite.' toothv flanks simultaneously, itis equally. applicable to machines having grindingwheels of disc or like formfwhich are adapted to grind one ank only of^ a tooth form during. a single: generating I cycle.

Iclaim:

. l; Apparatus for` grinding `gear-like elements comprising a .supporting basefframe, a worlrsupiporting head, a work-supportingspindle rotatably mounted in said work supporting head, said work supporting head being slideably mounted for reciprocating: movement.: on'. said'i base fram-errv in* a direction perpendicular; to. thevv axis' of' rotation oflsaid spindle, ai grinding 'head' mounted on said base frame adjacent one end of said work supporting.. spindle, meansfor rotatably adjusting said. headabout an axisperpendicularzto the axis of said spindle, said grinding: head including upper.v and lower" portions,l said upper portion being pivotally connected to said, lower portion, locking means for anchoring said portions in predeterminedangularposition with respect to each-.athenay grinding. assembly carried by said upper portionrof saidgrinding head, said grindingassembly being reciprocably mounted thereonsaid grin'dingassembly including a grinding wheeland supportingspindleand.means for. driving-saidzspindle 2.. Apparatus: for.. grindingl gears-like elements comprisingfaxsupporting base frame, a' work supiporting fheadi. a: .work supporting spindle rotatablymounted in' saidiworl3-supporting head, said work supporting-head, beingslideably mounted for reciprocatingmovementon said base :frame in a direction perpendicular to the axis of rotation of said spindle, a drum-likel element coaxially arranged with respect to, and anchored to said spindle, metallic tapes anchored to said drum, surrounding'the same, and each having one end thereof anchored:V to said base frame whereby reciprocation of said Work supporting head'will effect rotationo said spindle, a grinding head mounted on said base frame adjacent one end of said work supporting spindle, means for rotatablyadjustingzsaid. head about an axis perpendicular to the axis of said spindle, said grinding head including. upper and lower portions, said upper portion being pivotally connected to said lower portion, locking means for anchoring said portions in predeterminedlangular position with respect to each other, a grinding assembly carried by said upper portion of said grinding head, said grinding assembly being reciprocably mounted thereon, said grinding assembly including a` grinding wheel and supporting spindleY and means 'for driving said spindle.

3. Apparatus for: grinding gear-like elements comprising a supporting base frame, a work supporting head,. a work supporting spindle journalled for rotation in said head, ways interconnecting said head with said base'frame and pro-k on' said base frame adjacent one end of 'said' workl supporting spindle; means for rotatably-adjusting said `headlaboutari-axis perpendicular to the axis of5 said' spindle, said' grinding head.` including upper andl lower portions, said upper portion being pivotallyv connected to" said lower portion; locking means for anchoring saidV portions in predetermined angular position with respect to each other', a grinding assembly carried 'bysaid upperportion oi lsaid grinding head said grinding,

assembly being reciprocably mounted thereon,

`saidy grinding assembly including a grinding -whcel and' supporting spindle and means for drivingsaid spindle.

4; Apparatus. for grinding gear-like elements.-

comprising a 'supporting base frame, a work supporting head, a work supporting spindle journalled for rotation in said head, ways interconnecting said head-with said base frame and providing means for reciprocating said head with respect to said base frame in a direction perpendicular to the axis of rotation of said spindle, means for locking a gear-like element to be ground on said spindle, index means for precisely adjusting the position of a gear to be ground with respect to said spindle, a drum-like element coaXially arranged with respect to and anchored to said spindle, metallic tapes anchored to and surrounding said drum and each having one end thereof anchored to said base frame whereby re iprocating movement oi said head will effect rotation of said spindle precisely in accordance with the magnitude of reciprocating move-a ment, a grinding head mounted on said base frame adjacent one end of said work supporting spindle, means for rotatably adjusting said head about an axis perpendicular to the axis of said spindle, said grinding head including upper and lower portions, said upper portion being pivotally connected to said lower portion, locking means for anchoring said portions in predetermined angular p sition with respect to each other, a grinding assembly carried by said upper portion ci said grinding head, said grinding assembly being reciprccably mounted thereon, said grinding assembly including a grinding wheel and supporting spindle and means for driving said spindle.

5. Apparatus for grinding gear-like elements comprising a supporting base frame, a work supporting head, a work supporting spindle rotatably mounted in said work supporting head, said work supporting head being slideably mounted ior reciprocating movement on said base frame in a direction perpendicular to the axis of rotation of said spindle, a grindingf head mounted on said base frame adjacent one end of said work supporting spindle, said grinding head comprising a l wer portion, an upper portion and a grinding assembly carried by said upper portion, said rinding head as a whole being rotatably mounted on said base frame for adjustable rotation about an axis perpendicular to the aine of rotation of said work supporting sian-dla means for locking said grinding head in predetermined adjusted position, the upper and lower portions ci said grinding head being pivotally connected together and means for locking upper and lower portions in predetermined angular adjustment with respect to each other, said grinding assembly comprising a grinding wheel and means for rotatably driving the same.

6. Apparatus for grinding gear-like elements comprising a sup-porting base frame, a work supporting head, a work supporting spindle rotatably mounted in said work supporting head, said work supporting head being slideably mounted for reciprocating movement on said base frame in a direction perpendicular to the axis of rotation of said spindle, a grinding head mounted on said base .trame adjacent one end of said work supporting spindle, said grinding head comprising a lower portion, an upper portion and a grinding assembly carried by said upper portion, said grinding head as a whole being rotatably mounted on said base Jframe for adjustable rotation about an axis perpendicular to the axis of rotation of work supporting spindle, means for locking said grinding head in predetermined adjusted position, the upper and lower portions of said grinding head being pivotally connected together and means for locking said upper and lower portions in predetermined angular adjustment with respect to each other, said grinding assembly including in combination, a base member reciprocably mounted on the upper portion of said grinding head, means for automatically effecting reciprocation of said base member with respect to said upper portion, a grinding Wheel spindle support carried by said base member, a spindle journalled in said support, a grinding wheel carried by said Spindle, and means on said base member for rotatably driving said grinding wheel and spindle.

7. In a machine for grinding gear-like elements, a supporting base, a grinding head assembly mounted on said supporting base and rotatable about a substantially vertical axis, means for locking said grinding head assembly in predetermined adjusted position about said axis, said grinding head comprising a lower portion, an upper portion, and a grinding assembly carried by said upper portion, said upper and lower portions being pivotally connected about a transverse axis, means for locking said upper and lower portions in predetermined pivotal position with respect to each other, said grinding assembly carried by said Lipper portion comprising a base member reciprocably mounted with respect to said upper portion, a spindle support carried by said base member, a spindle journalled in said support, a grinding wheel carried by said spindle in a plane substantially parallel to the direction of reciprocation of said base, and means mounted on said base portion for driving said spindle and grinding wheel.

8. In a machine for grinding gear-like elements, a supporting base, a grinding head assembly mounted on said supporting base and rotatable about a substantially vertical axis, means for locking said grinding head assembly in predetermined adjusted position about said axis, said grinding head comprising a lower portion, an upper portion, and a grinding assembly carried by said upper portion, said upper and lower portions being pivotally connected about a transverse axis, means for locking said upper and lower portions in predetermined pivotal position with respect to each other, said grinding assembly carried by said upper portion comprising a, base member reciprocably mounted with respect to said upper portion, a spindle support carried by said base member, a spindle journalled in said support, a grinding wheel carried by said spindle, and means mounted on said base portion for driving said spindle and grinding wheel, crank means carried by the upper portion of said grinding head, said crank means engaging the base of said grinding assembly whereby to effect reciprocation thereof with respect to said upper portion, and motor means for driving said crank means.

JOSEPH RILEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,351,580 Maag et al Aug. 31, 1920 1,551,167 Orlow Aug, 25, 1925 2,187,062 Sykes Jan. 16, 1940 2,207,018 Linse et al July 9, 1940 2,364,542 'Miller Dec. 5, 1944 

